Wet/dry vacuum cleaners are devices that provide suction to pick up solid and liquid material from a surface. They are commonly used to clean garages, basements, workshops, construction sites, and other places where a combination dust, dirt, water, and other debris tend to collect. Wet/dry vacuum cleaners typically include a tank with an open top and a removable lid covering the open top. Typically, the lid houses a motor for driving a vacuum impeller. During operation, the vacuum impeller creates low pressure in the tank which draws solids, liquids, and gases therein.
Once full, the tank must be emptied by the user. The user can remove the lid and tilt the tank to empty its contents. However, this task can be cumbersome since the tank is usually heavy and unwieldy once full. Some wet/dry vacuum cleaners incorporate a port at the bottom of the tank that can be opened to drain liquid from inside the tank. However, draining the tank is feasible only if a floor drain or sewer is nearby.
Some wet/dry vacuum cleaners include a pumping mechanism which can be used to eject the contents of the tank. These wet/dry vacuum cleaners typically have an elongated motor shaft on which are mounted a vacuum impeller for drawing material into the tank and a pump impeller for discharging liquid from the tank. When the vacuum cleaner is used to suction liquid, it is generally preferred that the fluid level inside the tank not rise above the vacuum impeller. Therefore, such wet/dry vacuum cleaners typically include an automatic shutoff mechanism which interrupts power to the motor in the event that the liquid in the tank rises above a certain level.
Conventional automatic shutoff mechanisms typically include a float connected directly to a power switch. The float is positioned in the tank so that it rises with the fluid level. The upward buoyant force of the float is typically transmitted directly to the switch via a transmission rod. In some cases, the upward buoyant force of the float may be insufficient to immediately turn OFF the switch, particularly if the switch is biased to its ON position by a spring and/or if the switch has become rigid due to rust and/or wear. As a result, the automatic shutoff mechanism may not turn OFF the switch until after the fluid level has risen above an undesirable level, or not at all if the switch is particularly stiff. Additionally, since the upward buoyant force of the float may be weak, conventional automatic shutoff mechanisms may be compatible with a limited number of switches and/or may require a sensitive switch, such as a microswitch, which can be expensive.
Accordingly, the present disclosure sets forth wet/dry vacuum cleaners and automatic shutoff assemblies that embody advantageous alternatives to existing wet/dry vacuum cleaners and automatic shutoff assemblies, and that may address one or more of the challenges or needs mentioned above, as well as provides other benefits and advantages.